Limits...
The cytokinesis gene KEULE encodes a Sec1 protein that binds the syntaxin KNOLLE.

Assaad FF, Huet Y, Mayer U, Jürgens G - J. Cell Biol. (2001)

Bottom Line: KEULE is characteristic of a Sec1 protein in that it appears to exist in two forms: soluble or peripherally associated with membranes.More importantly, KEULE binds the cytokinesis-specific syntaxin KNOLLE.Sec1 proteins are key regulators of vesicle trafficking, capable of integrating a large number of intra- and/or intercellular signals.

View Article: PubMed Central - PubMed

Affiliation: Genetics and Microbiology Institute, Ludwig Maximilians University, D-80638 Munich, Germany. fassaad@andrew2.stanford.edu

ABSTRACT
KEULE is required for cytokinesis in Arabidopsis thaliana. We have positionally cloned the KEULE gene and shown that it encodes a Sec1 protein. KEULE is expressed throughout the plant, yet appears enriched in dividing tissues. Cytokinesis-defective mutant sectors were observed in all somatic tissues upon transformation of wild-type plants with a KEULE-green fluorescent protein gene fusion, suggesting that KEULE is required not only during embryogenesis, but at all stages of the plant's life cycle. KEULE is characteristic of a Sec1 protein in that it appears to exist in two forms: soluble or peripherally associated with membranes. More importantly, KEULE binds the cytokinesis-specific syntaxin KNOLLE. Sec1 proteins are key regulators of vesicle trafficking, capable of integrating a large number of intra- and/or intercellular signals. As a cytokinesis-related Sec1 protein, KEULE appears to represent a novel link between cell cycle progression and the membrane fusion apparatus.

Show MeSH

Related in: MedlinePlus

Cytokinesis defects in keule embryos A and B depict histological embryo sections (A) wild-type (triangular) (B) keule (delayed in their development). Note the large, irregularly shaped multinucleate cells in keule mutants. Bar: (A) 50 μm; (B) 20 μm.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2195996&req=5

Figure 1: Cytokinesis defects in keule embryos A and B depict histological embryo sections (A) wild-type (triangular) (B) keule (delayed in their development). Note the large, irregularly shaped multinucleate cells in keule mutants. Bar: (A) 50 μm; (B) 20 μm.

Mentions: Given the complexity of plant cytokinesis, surprisingly few genes have been identified by mutation. Genes required for cytokinesis in somatic plant cells fall into two classes. Although genes in the first class are required for the proper orientation of the plane of division, genes in the second class are required for the execution of cytokinesis. fas or tonneau and tangled (for review see Smith 1999) mutants define the first class of cytokinesis genes. The cyd mutants of pea (Liu et al. 1995) and Arabidopsis (Yang et al. 1999b) and the KNOLLE (Lukowitz et al. 1996) and KEULE (Assaad et al. 1996) genes of Arabidopsis fall into the second class. keule and knolle mutants die as seedlings in which rudiments of all body parts can be recognized and are characterized by the incidence of grossly enlarged, irregularly shaped cells (Assaad et al. 1996; Lukowitz et al. 1996). Light and electron microscopy showed that dividing cells in cyd, knolle, and keule mutants are often multinucleate, with gapped or incomplete cross walls, which defines these mutants as cytokinesis defective (Liu et al. 1995; Assaad et al. 1996; Lukowitz et al. 1996). The multinucleate cells are invariably enlarged (Assaad et al. 1996) and account for the rough surface and bloated appearance of these cytokinesis mutants. The keule phenotype (recapitulated in Fig. 1) highlights the importance of cytokinesis in cellular differentiation and morphogenesis in plants (Assaad et al. 1996).


The cytokinesis gene KEULE encodes a Sec1 protein that binds the syntaxin KNOLLE.

Assaad FF, Huet Y, Mayer U, Jürgens G - J. Cell Biol. (2001)

Cytokinesis defects in keule embryos A and B depict histological embryo sections (A) wild-type (triangular) (B) keule (delayed in their development). Note the large, irregularly shaped multinucleate cells in keule mutants. Bar: (A) 50 μm; (B) 20 μm.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2195996&req=5

Figure 1: Cytokinesis defects in keule embryos A and B depict histological embryo sections (A) wild-type (triangular) (B) keule (delayed in their development). Note the large, irregularly shaped multinucleate cells in keule mutants. Bar: (A) 50 μm; (B) 20 μm.
Mentions: Given the complexity of plant cytokinesis, surprisingly few genes have been identified by mutation. Genes required for cytokinesis in somatic plant cells fall into two classes. Although genes in the first class are required for the proper orientation of the plane of division, genes in the second class are required for the execution of cytokinesis. fas or tonneau and tangled (for review see Smith 1999) mutants define the first class of cytokinesis genes. The cyd mutants of pea (Liu et al. 1995) and Arabidopsis (Yang et al. 1999b) and the KNOLLE (Lukowitz et al. 1996) and KEULE (Assaad et al. 1996) genes of Arabidopsis fall into the second class. keule and knolle mutants die as seedlings in which rudiments of all body parts can be recognized and are characterized by the incidence of grossly enlarged, irregularly shaped cells (Assaad et al. 1996; Lukowitz et al. 1996). Light and electron microscopy showed that dividing cells in cyd, knolle, and keule mutants are often multinucleate, with gapped or incomplete cross walls, which defines these mutants as cytokinesis defective (Liu et al. 1995; Assaad et al. 1996; Lukowitz et al. 1996). The multinucleate cells are invariably enlarged (Assaad et al. 1996) and account for the rough surface and bloated appearance of these cytokinesis mutants. The keule phenotype (recapitulated in Fig. 1) highlights the importance of cytokinesis in cellular differentiation and morphogenesis in plants (Assaad et al. 1996).

Bottom Line: KEULE is characteristic of a Sec1 protein in that it appears to exist in two forms: soluble or peripherally associated with membranes.More importantly, KEULE binds the cytokinesis-specific syntaxin KNOLLE.Sec1 proteins are key regulators of vesicle trafficking, capable of integrating a large number of intra- and/or intercellular signals.

View Article: PubMed Central - PubMed

Affiliation: Genetics and Microbiology Institute, Ludwig Maximilians University, D-80638 Munich, Germany. fassaad@andrew2.stanford.edu

ABSTRACT
KEULE is required for cytokinesis in Arabidopsis thaliana. We have positionally cloned the KEULE gene and shown that it encodes a Sec1 protein. KEULE is expressed throughout the plant, yet appears enriched in dividing tissues. Cytokinesis-defective mutant sectors were observed in all somatic tissues upon transformation of wild-type plants with a KEULE-green fluorescent protein gene fusion, suggesting that KEULE is required not only during embryogenesis, but at all stages of the plant's life cycle. KEULE is characteristic of a Sec1 protein in that it appears to exist in two forms: soluble or peripherally associated with membranes. More importantly, KEULE binds the cytokinesis-specific syntaxin KNOLLE. Sec1 proteins are key regulators of vesicle trafficking, capable of integrating a large number of intra- and/or intercellular signals. As a cytokinesis-related Sec1 protein, KEULE appears to represent a novel link between cell cycle progression and the membrane fusion apparatus.

Show MeSH
Related in: MedlinePlus